By analyzing the cell-phone data of 24 British students, researchers from Oxford University noticed patterns in communication that indicate that, in general, people don't have the wherewithal to maintain too many close, intimate relationships. Maybe due to schedule overload, emotional limits, or some combination of both. "Because of these constraints individuals cannot increase the number of friends they communicate with at maximum rate, but most downgrade (or drop) some individuals if they wish to add new ones to their preferred network at high level of emotional intensity," the study says.

While Taylor Swift somehow defies this theory, once you hit that finite number of friends (the number varies from person to person), the brain enacts the same one-in, one-out policy as a club bouncer. New friend enters, old friend leaves.

Does this mean we all have a subconscious short list of friends? And there is at least one friend — maybe the one who is always late, or still owes you money, or humblebrags too much — who you could easily put on the chopping block? Oh my god, is it me?

Thank you, Academyof Science, for debunking my favorite elementary-school song: "Make new friends, but keep the old." Instead, let's teach kids the truth: "Make new friends, but be prepared to ditch the old. One is silver and the other your brain just physically cannot acknowledge anymore even if she was in your wedding and you used to call her three times a daaaaaay."